The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes at least one disk (such as a magnetic disk, magneto-optical disk, or optical disk), a spindle motor for rotating the disk, and a head stack assembly (HSA). The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly includes at least one head, typically several, for reading and writing data from and to the disk. In an optical disk drive, the head will typically include a mirror and objective lens for reflecting and focusing a laser beam on to a surface of the disk. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached heads are moved relative to tracks disposed upon the disk.
A hole may be formed through the disk drive base. The hole may be utilized to provide access to the disk once the disk drive is assembled. For example, the disk may be accessed for writing servo control data onto the disk. In order to prevent contamination from entering the disk drive a seal is disposed over the hole. The seal typically includes a metal layer that is attached to the disk drive base with a pressure sensitive adhesive. The metal layer is used to block particulate matter and also serves as a vapor barrier.
The action of peeling a flexible planar insulative layer off a planar surface may cause the insulative layer to become charged with one polarity while the planar surface would attain a potential of opposite polarity. This phenomenon is called tribocharging or triboelectrification. As such, static electricity may be generated during the removal of a seal from its backing just prior to installation. Static electricity may also be generated during removal of a seal from the disk drive housing. Because the surfaces are insulative, these charges may not be dissipated and have the possibility to build to an eventual undesirable discharge. Such a discharge can damage sensitive electrical components within a disk drive.
Accordingly, it is contemplated that there is need in the art for a seal for use with a disk drive housing hole that is more likely to mitigate electrostatic discharge events.